The present disclosure is related to automatic transfer switches. More particularly, the present disclosure is related to automatic transfer switches having integral protection functions.
Automatic transfer switches have become common in many industrial and residential power distribution systems. Automatic transfer switches are typically used to automatically transfer power distributed from two or more power sources to a load. In the industrial setting, many industrial facilities are configured to receive power from two or more sources. These sources can be different power grids, different points on the same power grid, a generator, and any combinations of the foregoing. Thus, in the event that power is unavailable or unsuitable from one of the sources, the automatic transfer switch can transfer the system to draw power from the second source.
In the residential setting, some homes have been equipped with a back-up electric generator, such as a solar array, a fuel cell, a gas generator, a windmill, and any combination thereof. The automatic transfer switch has been used to provide power from the back-up generator in the event of a power outage from the local utility company.
However, the complexity and cost of prior systems having automatic transfer switches have limited their utility in many applications. Accordingly, there is a need for lower cost, lower complexity systems having automatic transfer switching and protection capabilities.